Large cables used in the telephone industry containing numerous individual conductors present several problems. First, the large size of the cables makes them rigid and inflexible, preventing the cable from being bent in a curve with a tight radius. In addition, bending one of these large cables to form a curve with a tight radius often tears the shielding material surrounding the conductors. This material is used to shield the conductors from electromagnetic interference. In response to these problems, the telephone industry has typically caused the outer sheath of the cable and shielding material to be torn away at the end of the cable so that the individual conductors may be connected to a piece of telephone equipment. Because the shielding material is removed, the exposed end of the cable becomes particularly susceptible to electromagnetic interference.
Attempts to solve this problem have been mostly unsuccessful. Typically, the telephone industry uses heat shrink foil in a curved configuration to attempt to shield the exposed ends of the cable. This method has several drawbacks. First, it is difficult to make a proper electrical connection between the shielding in the cable and the heat shrink foil. In addition, the industry has difficulty making a solid electrical connection between the heat shrink foil and ground in the device to which the cable is attached. The inability to ground successfully the cable shield leads to increased susceptibility to electromagnetic interference.
The industry also attempts to solve this problem by attaching a crimp lug to the end of the shielding material inside the cable and attaching the shield to ground through a wire attached to the crimp lug. This method, although grounding the cable shielding more effectively than the heat shrink foil method, leaves the individual conductors unshielded at the end of the cable, thereby making them more susceptible to electromagnetic interference.